Duane hull



D. HULL.

No. 271,852. Patented Feb, 6, 1'883.

V UNrrED STATES PATENT OFFI E,

DUANEHULL, or MILLERTON, NEW YORK.

'LOCK N-'r AND BOLT;

SPECIFICATION forriing part of Letters Patent No. 271,852, dated February 6, 1883.`

` Applicationfiledd'une 9,1882. (Moder) To all whom it may concern:

Be it known that I, DUANE 'HULL, a citizen of the United States, residing at Millerton, in the county of Dutchess and State of New York, have invented certain new and useful Improvements in Lock Nuts and Bolts; and 1 do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertaius to make and use the same.

My invention relates to 'improvements in that classof lock-huts in which the looking of the nut upon the bolt is eft'ected by the different shape of the threads, either of the bolt or of the nut, which is caused `by the -act of applying the nut. V

,It is knowmthat patents have heretofore a been granted in which the threads of the bolt -the same shape ofthe bolt-thread, and the thread is of uniform pitch only part way, or a 'portion ot' the thread, While the remainder of the nut-thread is thicker at'the edge than the bolt-thread and hasa groov'e enlarged by deepening at the bottom, so thatthe nutcompresses the bolt between the thicker edges ot' the nutthreads. i

Myinvention consists in forming the threads ofthe bolt and nut ot' uniform; pitch from center to center of thethreads, and making either the nut with a square thread and the bolt with a V-thread, or, vice vers-a, the bolt with a V- thread and the nut with asquare thread. When the two difierentshaped,threads are brought together the square threads are forced into the spaces of the V-threads, thus impinging on three points-Wiz., on the two sides of the V- thread and its point, While the square thread' .impinges with its two points or edges and its base against the V-thread. By this means the 'following resultis obtained: the excessive fric tion of the threadstends to hold the nut firmly in its place and preveuts the nut becoming loosened by concussion or vibration, and any tendency of the nut to unscrew itself is effectu y tion of a bolt with V-thread and a nut with square thread screwed together. Fig. 6 is an enlarged view ot a part-ot Fig. 5. Fig. 7 is a side view of part of a bolt with. a modified form of the thread, and Fig. 8 is a section of a nut with similar thread.

In Fig. 1 of the drawings, A represents a bolt of three-quarter-inch diameter, having a V-thread cut upon it, and such a bolt has ordinarily' ten threads to theinch, and the nut B (shown in Fig. 2) has a square thread, and must .have also ten threads to the inch to fit the bolt. In Figs. 3 and 4 the threads are re- Versed-'. e., the bolt is`provided with a square thread and the nut with a V-thread. In Fig. 5 the bolt has a V-thread and the nut a square thread, and they are screwed together, and the manner ot' interlocking each other is shown better ,in the enlarged Fig. 6. In Figs. 7 and 8 the threads are ronnded at the top and'bottom, instead of being square.

As is well known to those skilled in the art, the depth of a V-thr'ead is ordinarily the same as the width at its base, or equal to the pitch from center to center of thread, while a square thread of the same pitch is half' as der-p and halt' as thick as the pitch,so that the square thread will fit snugly between the inclined parts of the V-thread and enter to half its depth, While the point ot' the V-thread will touch the base of square thread, thus impinging at three points. By thus bringing the two different 'kinds of threads together the the manner shown, and for the purpose speci- Io fied.

In testimony whereof I hereby affix my signature in presence of two Witnesses.

DUANE HULL.

Witnesses 3 LLOYD F. KELEHER, F. M. HEATON. 

